1. Field Of The Invention
This invention relates to an improved skin care composition for moisturizing and conditioning the skin. In particular, it relates to a cosmetically acceptable skin conditioning lotion or cream having an emulsified petrolatum or mineral oil base.
2. Description Of The Prior Art
Consumers have long desired a moisturizing and conditioning preparation in the form of a hand and body lotion or cream which, when applied, provides cosmetically acceptable tactile properties. The desirable properties of mineral oils and petrolatum have long been recognized primarily because of their beneficial effects on the skin. These ingredients are neutral, stable, odorless and substantially non-volatile at atmospheric conditions.
In particular, petrolatum has been used both alone, and as an ingredient in skin care products, for over 50 years. It is believed to be helpful in skin care, because it is occlusive and causes moisture to accumulate in the stratum corneum. Recently, A. M. Kligman, a respected research dermatologist, commented in a scientific paper titled "Regression Method For Assessing the Efficacy of Moisturizers" Cosmetics and Toiletries, Vol. 93, pages 27-35, Apr. 1, 1978, that when it comes to efficacy, petrolatum is the unrivaled moisturizer. Kligman reported that petrolatum is a tenacious substance which stays in place, filling in the irregularities and smoothing the surface (of the skin) for many hours. Kligman postulated that petrolatum and other effective greases, resist wear-off, reduce friction and roughness and perhaps, most importantly of all, contain substances which cross the horny layer barrier, altering the epidermis so that it does not desquamate abnormally, when the dew point is low.
Kligman believed that moisturizers have undisclosed pharmacologic effects on epidermal physiology. He further observed that:
"The creation of a moisturizer is still an art, a trial and error endeavor resting on a weak scientific foundation. One cannot sit at a desk and compose a superior moisturizer on rational principles unless of course aesthetics are ignored."
It has long been known that petrolatum is extremely difficult to formulate in a pleasing aesthetic state and, therefore, it is not present in many commercially available skin care products. Petrolatum or petroleum jelly, when applied to the skin, is greasy and cosmetically unacceptable. Attempts have been made to emulsify petrolatum in a cream or lotion form in order to reduce its greasy and unacceptable tactile properties, when applied to the skin. Petrolatum per se in lotion form is inherently unstable. In general, by adding conventional water-soluble detergent emulsifiers to stabilize the petrolatum or mineral oil, the moisturizing properties of the petrolatum are unacceptably reduced.
As employed herein the term "conditioning" relates to the deposition of a palpable emollient film on the skin, which works to retard the loss of moisture from the epithelium and to maintain or restore the softness and smoothness of the skin surface. As employed herein the term "moisturizing" relates to the formation of a cosmetically acceptable film on the skin which reduces transepidermal water loss (TEWL). A product "moisturizes" when water which is normally lost to the atmosphere is accumulated in the stratum corneum. This accumulation causes the skin to be moisturized.
A satisfactory skin care composition having superior moisturizing and conditioning properties with cosmetically acceptable tactile properties should exhibit satisfactory feel, lubricity and absorption when applied to the skin. In particular, the composition should exhibit good consistency, should apply evenly to the skin, should be absorbed rapidly and should dry quickly. After application, the skin should feel smooth and clean. The composition should assist in relieving the tight feeling of dry skin and should soothe irritated skin.
Until now, prior art and commercially available cosmetic formulations have failed to achieve all the aforementioned desired properties. In U.S. Pat. No. 3,818,105 there is disclosed a composition including cetyl alcohol, a fattyalkyl dimethylbenzyl ammonium compound and mineral oil in a skin lubricant formulation. Optional ingredients include an organic ester dispersion media, humectants, white oil and petrolatum.
U.S. Pat. No. 4,137,302 discloses cosmetic compositions containing emollients including cetyl alcohol, isopropyl palmitate and petrolatum. Various cationic emulsifiers are also disclosed.
U.S. Pat. No. 3,829,563 discloses petrolatum and fatty alcohols in a foaming detergent. U.S. Pat. No. 3,666,690 teaches a skin cleansing composition including mineral oil, a specific cationic surface active agent, a nonionic surface active agent, humectants and thickeners. Cosmetic compositions containing petroleum jelly in combination with the usual cosmetic ingredients are disclosed in U.S. Pat. Nos. 3,392,040, 3,609,102 and 3,981,990.
Recently, attempts have been made to improve skin care compositions with the introduction of such products as Wondra, Vaseline Intensive Care Lotion and Sensuously Silky. These products are subject to various defects. In general, the compositions provide a film which is palpably oily and greasy to the touch upon application. The applied films tend to be removed by water without much resistance and do not provide a level of moisturizing which is deemed cosmetically acceptable to users.